All essentials

Drop the filing and tell me the limit.

Free tool

Split PDF by Size

Split a PDF into the fewest parts that each stay under a file size limit — the cap CM/ECF and most e-filing portals enforce. Page boundaries are respected and each part is named by its range.

Good to know

  • Every part is written and measured, not estimated — a PDF's size does not follow its page count.
  • Presets cover the common CM/ECF caps; type your own if your court differs.
  • A single page bigger than the limit is reported by page number rather than silently split.

Your files stay on your machine

This tool runs entirely inside your browser tab. Nothing is uploaded, stored, or sent to a server — close the tab and every trace is gone.

These are the free ones — see the full suite

How big a file can it take?

There is no upload, so there is no upload limit — but the work happens in this tab, which means your browser’s memory is the budget. Nothing here will refuse a file for being large; a big enough one simply gets slow and, eventually, reloads the tab. The figures below are rules of thumb on a desktop browser, not enforced caps. On a phone or tablet, expect a good deal less.

  • Parts are written and weighed rather than estimated, so the document is saved several times over — the slowest tool here on a long file, and comfortable to around 500 pages.
  • A tight limit means more parts and therefore more passes; raising the cap where your court allows it is the quickest way to speed a big run up.

Password-protected PDFs are declined whatever their size — unlock the file first. If a run does die on a long document, splitting it into volumes and working through them one at a time is the reliable way round it.

Built on open source

The Essentials tools do their work in your browser using these open-source libraries, used under the licenses below. Each remains the copyright of its authors.

  • pdf-libMIT · creates and edits the PDFs you download
  • pdf.jsApache-2.0 · reads your PDF and renders the page previews
  • SheetJS (xlsx)Apache-2.0 · reads Excel workbooks — .xlsx, .xls, .xlsb and .ods
  • hyparquetMIT · reads Apache Parquet files
  • hyparquet-compressorsMIT · the Parquet codecs beyond Snappy — Gzip, Zstd, Brotli, LZ4
  • JSZipMIT · bundles multi-file results into one ZIP
  • LucideISC · the icons throughout these tools
  • ReactMIT · the interface itself
  • Next.jsMIT · builds and serves these pages

pdf.js ships fallback fonts contributed by Foxit Software, redistributed here as part of pdf.js. JSZip is dual-licensed; it is used here under the MIT license.